Mail & Guardian reporter
The value of pregnant women’s urine just hit the equivalent of a Wall Street high this week, when scientists published the discovery of a protein that can reportedly wipe out tumours caused by Kaposi’s sarcoma, an Aids-related cancer, and inhibit the reproduction of HIV, the virus that causes Aids.
The protein – an associated factor of the hormone human chronic gonadotropin (hCG) – is found in women’s urine during early pregnancy. The link was accidentally discovered a few years ago by a researcher studying Kaposi’s sarcoma, a potentially lethal disorder that causes skin lesions in Aids sufferers.
Researchers were creating Kaposi’s in mice for study, but only some mice were being affected. The cancer-free mice had two things in common: they were female and pregnant.
In 1995 researchers reported that doses of commercial hCG preparations killed Kaposi’s cells in the laboratory and shrank Kaposi’s tumors in mice.
The following year, scientists reported that injecting commercial hCG preparations into tumours could often make them disappear in human patients. In addition, studies in which the preparations were injected into patients’ bloodstreams sometimes showed a decline in the amount of HIV in their blood.
But commercial preparations derived from pregnant women’s urine contain many contaminants which researchers suspected might really be responsible.
The latest chapter of the story appears in the April issue of the journal Nature Medicine in which scientists present evidence that a substance called HAF, an hCG-associated factor, is responsible. HAF can be found in hCG preparations and in urine from pregnant women, they reported. Once purified and analyzed, it might become a new treatment for Kaposi’s and HIV infection, said Dr Robert Gallo of the University of Maryland’s Institute of Human Virology.
The new paper shows HAF sharply inhibited growth of Kaposi’s sarcoma tumours in mice and suppressed HIV in the test tube. It showed signs of promoting the growth of bone marrow cells in the test tube – hope of protection from marrow damage caused by cancer treatments. HAFalso boosted the immune system by increasing infection-fighting T cell counts.
Because the protein is a human product, it is non-toxic and has few side effects.